This invention relates in general to collating and more particularly to a machine for collating signatures in a saddle format.
Many magazines and other publications of multiple pages are arranged in a saddle format, meaning that the individual signatures which form these publications are laid one within the other instead of one on top of the other as in a so-called perfect binding. The folds of all of the signatures lie along a common line, and several staples are usually driven through these folds to complete the saddle binding, although in small saddle bound publications, such as inserts for newspapers, the staples are often omitted.
The typical saddle binding machine has an endless gathering chain, the upper pass of which runs beneath a succession of feeding devices, each of which is capable of depositing a different signature onto the gathering chain. In particular, each feeding device contains a pocket in which the signatures as they are delivered from the printing press are stacked. Thus, the signatures rest one upon the other in the pocket of the feeding device. In addition, the feeding device has an apparatus for extracting signatures one at a time from the pocket, for opening each signature after it is extracted, and for releasing the signature at the proper instant so that it drops onto the chain with its folds along the upper edge of the chain and its pages draping downwardly to the sides of the chain. Thus, as the chain moves under the feeding devices it acquires more and more signatures, and upon emerging from the last feeding device it should have enough signatures compiled in the proper order to constitute the full publication. Thereafter, the chain discharges the compiled signatures onto a conveyor which extends laterally away from the gathering chain. Along this lateral conveyor a cover may be applied and staples are driven through the folds of the cover and compiled signatures to hold them together in a saddle binding. The cover and signatures are also trimmed along this conveyor so that their margins register. The conveyor stacks the publication upon discharge and the stacks are usually removed by hand from the collating machine.
A conventional saddle binding machine of the foregoing construction may contain 18 or more feeding devices. Such a machine is about 85 feet long and the lateral conveyor, along which the trimming and stapling occur, occupies about 28 feet. The entire machine therefore consumes a considerable amount of plant space. It also requires a relatively large number of individuals to operate it, for normally one attendant can load only about four pockets. Another individual is required to monitor the gathering chain to insure that each feeding device deposits a signature on it, and this individual usually attends to any disruptions or misfeeds. The machines are not only costly in terms of the labor required to operate them, but they are also quite expensive in their own right.
Small publications containing only a few signatures do not justify the large investment required for the typical saddle binding machine. Nevertheless, small publications are compiled on such machines, for want of any other type of machine to assemble them.